Conventionally, in adding software to an application system as plug-in software, the software to be added needs to be modularized and connected to the application system via an interface (see JP-A-2003-108370, for example). The interface is defined individually for each module or defined in common in accordance with the function of the module. However, even in a case where the interfaces are defined in common, each of the modules require a plurality of interfaces because modules grow in sizes and become multifunctional. Therefore, since it becomes possible for a plurality of modules to be connected to a common interface, pointer connectable to each of the plurality of modules is provided with a unique name capable of identifying both the module and the interface thereof. By providing the unique names, the modules becomes connectable to necessary interfaces, however, the number of the unique names increases, and the unique names become more complicated.